Renal function in hepatosplenic schistosomiasis--an assessment of renal tubular disorders.

BACKGROUND: Renal involvement in Schistosoma mansoni infection is not well studied. The aim of this study is to investigate the occurrence of renal abnormalities in patients with hepatosplenic schistosomiasis (HSS), especially renal tubular disorders. METHODS: This is a cross-sectional study with 20 consecutive patients with HSS followed in a medical center in Maceió, Alagoas, Brazil. Urinary acidification and concentration tests were performed using calcium chloride (CaCl2) after a 12-h period of water and food deprivation. The biomarker monocyte chemoattractant protein 1 (MCP-1) was quantified in urine. Fractional excretion of sodium (FENa+), transtubular potassium gradient (TTKG) and solute-free water reabsorption (TcH2O) were calculated. The HSS group was compared to a group of 17 healthy volunteers. RESULTS: Patients' mean age and gender were similar to controls. Urinary acidification deficit was found in 45% of HSS patients. Urinary osmolality was significantly lower in HSS patients (588 ± 112 vs. 764 ± 165 mOsm/kg, p = 0,001) after a 12-h period of water deprivation. TcH2O was lower in HSS patients (0.72 ± 0.5 vs. 1.1 ± 0.3, p = 0.04). Urinary concentration deficit was found in 85% of HSS patients. The values of MCP-1 were higher in HSS group than in control group (122 ± 134 vs. 40 ± 28 pg/mg-Cr, p = 0.01) and positively correlated with the values of microalbuminuria and proteinuria. CONCLUSIONS: HSS is associated with important kidney dysfunction. The main abnormalities found were urinary concentrating ability and incomplete distal acidification defect, demonstrating the occurrence of tubular dysfunction. There was also an increase in urinary MCP-1, which appears to be a more sensitive marker of renal damage than urinary albumin excretion rate

General laboratory parameters of hepatosplenic schistosomiasis patients and controls.

<p>Values are expressed as mean ± SD. Significant P<0.05 <i>vs</i> control by Student <i>t</i> test. P_Na+, plasma sodium; P_K+, plasma potassium; P_Ca2+, plasma calcium; P_P, plasma phosphorus; P_Cl-, plasma chloride; PMg2+, plasma magnesium AST, aspartate aminotransferase; ALT, alanine aminotransferase; GGT, gamma glutamyl transferase; INR, international normalized ratio.</p><p>General laboratory parameters of hepatosplenic schistosomiasis patients and controls.</p

Demographic and clinical characteristics of the study population.

<p>Data are shown as mean ± SD or percentages. Significant P <0.05 <i>vs.</i> control by Student' <i>t</i> and Fisher's exact tests.</p><p>Demographic and clinical characteristics of the study population.</p

Correlation between urinary MCP-1 and albuminuria in schistosomiasis patients.

<p>Correlation between urinary MCP-1 and albuminuria in schistosomiasis patients.</p

Comparison of renal function in hepatosplenic schistosomiasis patients and controls.

<p>Values are expressed as mean ± SD. Significant P <0.05 <i>vs.</i> control by Student <i>t</i> test. P_Cr, plasma creatinine; P_Ur, plasma urea; GFR, glomerular filtration rate; MCP-1, Monocyte Chemotactic Protein-1 FE_Na+, fractional excretion of sodium; FE_Mg++, fractional excretion of magnesium; FE_K+, fractional excretion of potassium; TTKG, transtubular potassium transport; TcH2O, reabsorption of free water solute.</p><p>Comparison of renal function in hepatosplenic schistosomiasis patients and controls.</p